USE OF AN ANTI-alpha-SYNUCLEIN ANTIBODY TO DIAGNOSE AN ELEVATED LEVEL OF alpha-SYNUCLEIN IN THE BRAIN

Abstract

This disclosure relates to the use of anti-α-synuclein antibody to diagnose an elevated level of α-synuclein in the brain. Specifically, the disclosure relates to the method of assessing the levels of α-synuclein in a blood plasma or CSF following administration to the test subject of an anti-α-synuclein antibody or antigen-binding fragment thereof, which can bind α-synuclein with sufficient activity to alter the net efflux of α-synuclein from brain to blood, or from brain to CSF.

What is claimed is: 
     
         1 . A method of diagnosing an elevated level of α-synuclein in the brain of a test subject comprising:
 (a) assaying the level of α-synuclein in a blood plasma sample obtained from the test subject at a specified interval following peripheral administration to the test subject of an anti-α-synuclein antibody or antigen-binding fragment thereof, wherein the antibody or fragment thereof can bind α-synuclein with sufficient affinity to alter the net efflux of α-synuclein from brain to blood; 
 (b) comparing the assayed level of the α-synuclein in the test subject to a reference standard; wherein the difference or similarity between the level of α-synuclein in the plasma sample and the reference standard correlates with the level of α-synuclein in the brain of the test subject. 
 
     
     
         2 . A method of diagnosing an elevated level of α-synuclein in the brain of a test subject comprising:
 (a) providing an anti-α-synuclein antibody or antigen-binding fragment thereof, wherein the antibody or fragment thereof can bind α-synuclein with sufficient affinity to alter the net efflux of α-synuclein from brain to blood; 
 (b) directing a healthcare provider to peripherally administer the antibody to the test subject and obtain a blood plasma sample from the subject at a specified time interval following administration; 
 (c) assaying the level of α-synuclein in the blood plasma sample; 
 (d) comparing the assayed level of α-synuclein in the test subject to a reference standard; wherein the difference or similarity between the level of the α-synuclein in the plasma sample and the reference standard correlates with the level of α-synuclein in the brain of the test subject. 
 
     
     
         3 . A method of diagnosing an elevated level of α-synuclein in the brain of a test subject comprising:
 (a) peripherally administering an anti-α-synuclein antibody or antigen-binding fragment thereof to the test subject, wherein the antibody or fragment thereof can bind α-synuclein with sufficient affinity to alter the net efflux of the α-synuclein from brain to blood; 
 (b) obtaining a blood plasma sample from the test subject at a specified time interval following administration, and submitting the sample for determination of the level of the α-synuclein; 
 (c) comparing the level of the α-synuclein in blood plasma sample to a reference standard; wherein the difference or similarity between the level of the α-synuclein in the plasma sample and the reference standard correlates with level of the α-synuclein in the brain of the test subject. 
 
     
     
         4 . A method of diagnosing an elevated level of α-synuclein in the brain of a test subject comprising:
 (a) assaying the level of α-synuclein in a CSF sample obtained from the test subject at a specified interval following peripheral administration to the test subject of an anti-α-synuclein antibody or antigen-binding fragment thereof, wherein the antibody or fragment thereof can bind α-synuclein with sufficient affinity to alter the net efflux of α-synuclein from brain to CSF; 
 (b) comparing the assayed level of the α-synuclein in the test subject to a reference standard; wherein the difference or similarity between the level of α-synuclein in the CSF sample and the reference standard correlates with the level of α-synuclein in the brain of the test subject. 
 
     
     
         5 . A method of diagnosing an elevated level of α-synuclein in the brain of a test subject comprising:
 (a) providing an anti-α-synuclein antibody or antigen-binding fragment thereof, wherein the antibody or fragment thereof can bind α-synuclein with sufficient affinity to alter the net efflux of α-synuclein from brain to CSF; 
 (b) directing a healthcare provider to peripherally administer the antibody to the test subject and obtain a CSF sample from the subject at a specified time interval following administration; 
 (c) assaying the level of α-synuclein in the CSF; 
 (d) comparing the assayed level of α-synuclein in the test subject to a reference standard; wherein the difference or similarity between the level of the α-synuclein in the CSF sample and the reference standard correlates with the level of α-synuclein in the brain of the test subject. 
 
     
     
         6 . A method of diagnosing an elevated level of α-synuclein in the brain of a test subject comprising:
 (a) peripherally administering an anti-α-synuclein antibody or antigen-binding fragment thereof to the test subject, wherein the antibody or fragment thereof can bind α-synuclein with sufficient affinity to alter the net efflux of the α-synuclein from brain to CSF; 
 (b) obtaining a CSF sample from the test subject at a specified time interval following administration, and submitting the sample for determination of the level of the α-synuclein; 
 (c) comparing the level of the α-synuclein in the CSF sample to a reference standard; wherein the difference or similarity between the level of the α-synuclein in the CSF sample and the reference standard correlates with level of the α-synuclein in the brain of the test subject. 
 
     
     
         7 . The method of any one of  claims 1  to  3 , further comprising comparing the level of the α-synuclein in the plasma sample to a plasma sample obtained from the test subject prior to administration of the anti-α-synuclein antibody or antigen-binding fragment thereof. 
     
     
         8 . The method of any one of  claims 4  to  6 , further comprising comparing the level of the α-synuclein in the CSF sample to a CSF sample obtained from the test subject prior to administration of the anti-α-synuclein antibody or antigen-binding fragment thereof. 
     
     
         9 . The method of any one of  claims 1  to  8 , wherein the reference standard comprises measured levels of α-synuclein in one or more control subjects, wherein the control subjects include normal healthy individuals, and individuals with synucleinopathies of varying severity. 
     
     
         10 . A method of tracking the α-synuclein level in the brain of a subject being treated for a synucleinopathic disease, comprising assaying the level of α-synuclein in the subject's blood plasma at a specified time following peripheral administration of an anti-α-synuclein antibody or antigen-binding fragment thereof, wherein the antibody or fragment thereof can bind α-synuclein with sufficient affinity to alter the net efflux of the α-synuclein from brain to blood; and wherein the α-synuclein level in the subject's blood plasma correlates with the level in the subject's brain. 
     
     
         11 . A method of tracking the α-synuclein level in the brain of a subject being treated for a synucleinopathic disease, comprising assaying the level of α-synuclein in the subject's CSF at a specified time following peripheral administration of an anti-α-synuclein antibody or antigen-binding fragment thereof, wherein the antibody or fragment thereof can bind α-synuclein with sufficient affinity to alter the net efflux of the α-synuclein from brain to CSF; and wherein the α-synuclein level in the subject's CSF correlates with the level in the subject's brain. 
     
     
         12 . The method of  claim 10 , further comprising assaying the level of α-synuclein in the subject's blood plasma at a specified time following additional peripheral administrations of the anti-α-synuclein antibody or antigen-binding fragment thereof, thereby plotting the change in the α-synuclein level in the subject's brain over time. 
     
     
         13 . The method of  claim 11 , further comprising assaying the level of α-synuclein in the subject's CSF at a specified time following additional peripheral administrations of the anti-α-synuclein antibody or antigen-binding fragment thereof, thereby plotting the change in the α-synuclein level in the subject's brain over time. 
     
     
         14 . The method of any one of  claims 1  to  13 , wherein the antibody or antigen-binding fragment thereof specifically binds to the same α-synuclein epitope as reference antibody comprising a VH and a VL, wherein the VH comprises SEQ ID NO: 2 and the VL comprises SEQ ID NO: 3. 
     
     
         15 . The method of any one of  claims 1  to  14 , wherein the antibody or antigen-binding fragment thereof competitively inhibits reference antibody comprising a VH and a VL, wherein the VH comprises SEQ ID NO: 2 and the VL comprises SEQ ID NO: 3 from binding to α-synuclein. 
     
     
         16 . The method of any one of  claims 1  to  15 , wherein the antibody or antigen-binding fragment thereof comprises a heavy chain variable region (VH) and a light chain variable region (VL), wherein the VH comprises a complementarity determining region-1 (VHCDR1) amino acid sequence of SEQ ID NO: 4 
     
     
         17 . The method of any one of  claims 1  to  16 , wherein the antibody or antigen-binding fragment thereof comprises a VH and a VL, wherein the VH comprises a complementarity determining region-2 (VHCDR2) amino acid sequence of SEQ ID NO: 5. 
     
     
         18 . The method of any one of  claims 1  to  17 , wherein the antibody or antigen-binding fragment thereof comprises a VH and a VL, wherein the VH comprises a complementarity determining region-3 (VHCDR3) amino acid sequence of SEQ ID NO: 6. 
     
     
         19 . The method of any one of  claims 1  to  18 , wherein the antibody or antigen-binding fragment thereof comprises a VH and a VL, wherein the VL comprises a complementarity determining region-1 (VLCDR1) amino acid sequence of SEQ ID NO: 7. 
     
     
         20 . The method of any one of  claims 1  to  19 , wherein the antibody or antigen-binding fragment thereof comprises a VH and a VL, wherein the VL comprises a complementarity determining region-2 (VLCDR2) amino acid sequence of SEQ ID NO: 8. 
     
     
         21 . The method of any one of  claims 1  to  20 , wherein the antibody or antigen-binding fragment thereof comprises a VH and a VL, wherein the VL comprises a complementarity determining region-3 (VLCDR3) amino acid sequence of SEQ ID NO: 9. 
     
     
         22 . The method of any one of  claims 1  to  21 , wherein the antibody or antigen-binding fragment thereof comprises a VH and a VL, wherein the VH comprises VHCDR1, VHCDR2, and VHCDR3 amino acid sequences of SEQ ID NOs: 4, 5, 6. 
     
     
         23 . The method of any one of  claims 1  to  22 , wherein the antibody or antigen-binding fragment thereof comprises a VH and a VL, wherein the VL comprises VLCDR1, VLCDR2, and VLCDR3 amino acid sequences of SEQ ID NOs: 7, 8, 9. 
     
     
         24 . The method of any one of  claims 1  to  23 , wherein the antibody or antigen-binding fragment thereof comprises a VH and a VL, wherein the VH comprises VHCDR1, VHCDR2, and VHCDR3 amino acid sequences of SEQ ID NOs: 4, 5, 6, and the VL, comprises VLCDR1, VLCDR2, and VLCDR3 amino acid sequences of SEQ ID NOs: 7 8, 9. 
     
     
         25 . The method of any one of  claims 1  to  24 , wherein the antibody or antigen binding fragment thereof comprises a VH amino acid sequence of SEQ ID NO: 2 and a VL amino acid sequence of SEQ ID NO: 3. 
     
     
         26 . The method of any one of  claims 1  to  25 , wherein the antibody or antigen binding fragment thereof is a single chain Fv fragment (scFv), an F(ab′) fragment, an F(ab) fragment, or an F(ab′) 2  fragment. 
     
     
         27 . The method of any one of  claims 1  to  26 , wherein the administering is by intravenous injection of the antibody. 
     
     
         28 . The method of any one of  claims 1  to  27 , wherein the antibody is human. 
     
     
         29 . The method of any one of  claim 1  to  9 , or  14 - 28 , wherein the specified time interval is less than a week. 
     
     
         30 . The method of  claim 29 , wherein the specified time interval is less than or equal to 24 hours. 
     
     
         31 . The method of  claim 30 , wherein the specified time interval is less than or equal to 3 hours. 
     
     
         32 . The method of any one of  claims 10 - 13 , wherein the synucleinopathic disease is selected from the group consisting of Parkinson's disease (PD), Parkinson's disease dementia (PDD), dementia with Lewy bodies (DLB), the Lewy body variant of Alzheimer's disease (LBVAD), multiple systems atrophy (MSA), pure autonomic failure (PAF), neurodegeneration with brain iron accumulation type-1 (NBIA-I), Alzheimer's disease, Pick disease, juvenile-onset generalized neuroaxonal dystrophy (Hallervorden-Spatz disease), amyotrophic lateral sclerosis, traumatic brain injury and Down syndrome.